{"id":74,"date":"2007-08-28T21:11:18","date_gmt":"2007-08-28T21:11:18","guid":{"rendered":"http:\/\/re-photo.co.uk\/?p=74"},"modified":"2007-09-01T09:26:18","modified_gmt":"2007-09-01T09:26:18","slug":"end-colour-fringing","status":"publish","type":"post","link":"http:\/\/re-photo.co.uk\/?p=74","title":{"rendered":"End Colour Fringing"},"content":{"rendered":"<p>The Nikon digital 10.5mm semi-fisheye is one of my favourite lenses, although it needs to be used sparingly. I wrote about it at some length for <a href=\"http:\/\/photography.about.com\/od\/lensesfordigital\/ss\/nikkorfisheye.htm\" target=\"_blank\">About.com<\/a> shortly after getting it, with various suggestions for using and altering the images it gives. Since then I&#8217;ve used it to create several images I feel proud of, subjects that just fitted the effect it gives, like this circle of druids at the spring equinox in London:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.mylondondiary.co.uk\/2007\/03\/21\/070321-d0185.jpg\" title=\"Druids in London (C) 2007, Peter Marshall\" alt=\"Druids in London (C) 2007, Peter Marshall\" height=\"301\" width=\"450\" \/><br \/>\n<em> Spring Equinox at Tower Hill, 2007<\/em><\/p>\n<p>Anyone reading this in Hungary who saw the recent &#8216;<em>Europe of Culture \u0096 the culture of urbanity<\/em>&#8216; show this year will have seen this picture I took at <a href=\"http:\/\/http:\/\/photography.about.com\/od\/europe\/ss\/contretype.htm\" target=\"_blank\">Contretype <\/a>in Brussels, where the circular stairway of the <em>Hotel Hannon<\/em> provided another ideal subject.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/buildingsoflondon.co.uk\/library\/brussels9571.jpg\" title=\"Hotel Hannon (C) 2005, Peter Marshall\" alt=\"Hotel Hannon (C) 2005, Peter Marshall\" height=\"299\" width=\"450\" \/><\/p>\n<p>But the lens does have one severe problem, chromatic aberration, which needs to be corrected at least for good large prints. For the Hungary show, I spent ages working on the file, removing some of the more noticeable colour fringing using Photoshop.<\/p>\n<p>But of course there are easier ways, and one of the best I&#8217;ve found is in Lightroom, which I now use for converting my RAW digital files. (People tell me the Nikon software does a good job, but  even several years and 2 camera bodies later I still can&#8217;t bring myself to pay for the software that Nikon really should have supplied free with the cameras.) It isn&#8217;t just useful for the 10.5 Nikkor, but almost all the images I take when I want to make critical large prints, as nearly all zoom lenses show some chromatic aberration at most focal lengths (the Nikon 18-200, for example,  is fine at 24mm, but away from this needs a little help.)<\/p>\n<p>If there is anyone using <strong>Lightroom<\/strong> who has yet to find this, or anyone still wondering if Lightroom is worth the money, in the Development mode there is a panel headed &#8216;<em>Lens Corrections<\/em>&#8216; with two and a half sections. The first part has two sliders to control chromatic aberration, one for Red\/Cyan and the other for Blue\/Yellow.  Here is a small section of an image taken by the 10.5mm, from close to a corner and at three times actual size to show the effect exagerated.<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/buildingsoflondon.co.uk\/Library\/lr_original.jpg\" title=\"3:1 section of original\" alt=\"3:1 section of original\" \/><br \/>\n<em>Before any correction &#8211; image at 3 times actual size<\/em><\/p>\n<p>And here it is after adding -46 Red\/Cyan and +32 Blue\/Yellow<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/buildingsoflondon.co.uk\/library\/lr_chromatic.jpg\" title=\"After Chromatic removal\" alt=\"After Chromatic removal\" height=\"331\" width=\"497\" \/><\/p>\n<p>There is still some colour  fringing, although it is a lot improved.  Below the two sliders is a &#8216;Defringe&#8217; setting that controls the removal of blue fringing found in many digital images. If set to &#8216;All edges&#8217; it finishes the job, giving an almost perfect result (and with a little tweaking of the sliders I could probably improve it slightly.) It actually makes the settings for chromatic aberration easier to determine if you set the &#8216;defringing&#8217; first.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/buildingsoflondon.co.uk\/library\/lr_definged.jpg\" title=\"Image defringed\" alt=\"Image defringed\" height=\"331\" width=\"497\" \/><\/p>\n<p>Lightroom will also do a little more for these images. Most pictures taken with the 10.5mm show some vignetting, usually giving images that are lighter at the corners. The lower half of the &#8216;Lens Corrections&#8217; panel can deal with this, often looking best with values around -35 for amount and 21 for midpoint.<\/p>\n<p>I spent some time playing with this today as I used the semi-fisheye for some pictures at Notting Hill Carnival over the weekend, which I&#8217;ll write about a little more later. Again it let me take pictures that could not have been taken any other way.<\/p>\n<p><em>Peter Marshall <\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Nikon digital 10.5mm semi-fisheye is one of my favourite lenses, although it needs to be used sparingly. I wrote about it at some length for About.com shortly after getting it, with various suggestions for using and altering the images it gives. Since then I&#8217;ve used it to create several images I feel proud of, &hellip; <a href=\"http:\/\/re-photo.co.uk\/?p=74\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">End Colour Fringing<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[3,4],"tags":[],"class_list":["post-74","post","type-post","status-publish","format-standard","hentry","category-my-own-work","category-technical"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/74","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=74"}],"version-history":[{"count":0,"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/74\/revisions"}],"wp:attachment":[{"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=74"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=74"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/re-photo.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=74"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}